Waterproof Temperature Sensor, DS18B20 (SEN-11050)

Temperature Sensor - Waterproof DS18B20 - SparkFun SEN-11050

This sealed digital temperature probe lets you precisely measure temperatures in wet environments with a simple 1-Wire interface.
The DS18B20 provides 9 to 12-bit (configurable) temperature readings over a 1-Wire interface so that only one wire (and ground) needs to be connected from a central microprocessor.
The measurement range of the DS18B20 itself is -55°C to+125°C, however on this unit the cable is not high temp rated. So this part should only be used to measure temps where the cable can be kept below 85°C.
A waterproof high-temperature sensor version is available where the whole assembly can be used up to 125°C

DS18B20 Wiring Pin Out:

• RED: Vcc
• BLACK: Ground
• WHITE: Signal

DS18B20 Features:

• 3.0-5.5V input voltage
• Waterproof
• -55°C to+85°C temperature range
• ±0.5°C accuracy from -10°C to +85°C
• 1 Wire interface

DS18B20 Dimensions:

• Probe Diameter: 7mm
• Probe Length: 26mm
• Overall length (including wire): 1800mm (6')

DS18B20 Specifications:

• Supply voltage: 3.0 to 5.5 V
• Standby current: 1 μA
• Active current: 1.5 mA
• Measuring range: -55 °C to + 85°C (-67 °F to +185 °F)
• Accuracy (Thermometer Error):
  • ±0.5 °C from -10 °C to +85 °C
  • ±1 °C from -30 °C to +100 °C
  • ±2 °C from -55 °C to +85 °C
• Resolution: 9-bit to 12-bit (programmable)
• Conversion time: < 750 ms (12-bit resolution)
• Communication protocol: 1-Wire® bus protocol

DS18B20+ Block Diagram:

Connecting DS18B20+ to Arduino:

You'll need to download the Arduino Librarys "OneWire" and "DallasTemp" which you can find below, and install them to your Arduino Libraries folder.
Connect your Arduino as per this diagram:

Notes:

• You don't need a Scottish Uno, and Uno will do!
• You only need one 4.7K resistor per circuit, no matter how many temperature sensors you add in a daisy chain formation

Example Arduino Code for DS18B20+:

[code lang="arduino"]
/* Example code for the DS18B20+ One-Wire Digital Temperature Sensor */
// Include Arduino libraries:
#include
#include
// Define the Arduino data pin connected to the 1-Wire bus:
#define ONE_WIRE_BUS 2
// Create a new instance of the oneWire class to communicate with any OneWire device:
OneWire oneWire(ONE_WIRE_BUS);
// Pass the oneWire reference to DallasTemperature library:
DallasTemperature sensors(oneWire);
void setup() {
// Begin serial communication at a baud rate of 9600:
Serial.begin(9600);
// Start up the library:
sensors.begin();
}
void loop() {
// Send the command for all devices on the bus to perform a temperature conversion:
sensors.requestTemperatures();
// Fetch the temperature in degrees Celsius for device index:
float tempC = sensors.getTempCByIndex(0); // the index 0 refers to the first device
float tempF = sensors.getTempFByIndex(0); // Fetch the temperature in degrees Fahrenheit for device index
Serial.print("Temperature: "); //Output to the serial monitor
Serial.print(tempC); // Print the temperature in Celsius
Serial.print(" \xC2\xB0");
Serial.print("C | ");
Serial.print(tempF);// Print the temperature in Fahrenheit
Serial.print(" \xC2\xB0");
Serial.println("F");
// Wait 1 second:
delay(1000);
}
[/code]

Documents:

• DS18B20 Datasheet
• OneWire (Arduino Library)
• DallasTemp (Arduino Library)